var a = {a:0}
var b = {b:1,c:2}
var c = {d:3,e:4}
var d = 'efg'
Object.assign(a,b,c)
console.log(a)
//{ a: 0, b: 1, c: 2, d: 3, e: 4 }
console.log(Object.assign({},b,c,d))
//{ '0': 'e', '1': 'f', '2': 'g', b: 1, c: 2, d: 3, e: 4 }


var aa = {a:1,b:2,c:3}
var ab = {b:22,c:22}
var ac = {c:33}
var abc = Object.assign({},aa,ab,ac)
console.log(abc)
console.log(JSON.stringify(abc))

var bb = { a:0 }
var copy = Object.assign({},bb)
console.log(copy)